Blood products

Primary blood components iaclude plasma, red blood cells (erythrocytes), white blood cells (leukocytes), platelets (thrombocytes), and stem cells. Plasma consists of water dissolved proteias, ie, fibrinogen, albumins, and globulins coagulation factors and nutrients. The principal plasma-derived blood products are siagle-donor plasma (SDP), produced by sedimentation from whole blood donations fresh frozen plasma (FFP), collected both by apheresis and from whole blood collections cryoprecipitate, produced by cryoprecipitation of FFP albumin, collected through apheresis and coagulation factors, produced by fractionation from FFP and by apheresis (see Fractionation, blood-plasma fractionation). 

Contamination of blood products with lymphocytes can lead to transfusion-induced reactions ranging from a mild fever to severe reactions such as alloimmunization and graft versus host disease (GvHD), in which the transfused lymphocytes (graft) survive the defensive immune reaction of the patient (host) and start a reaction which destroys the cells of the host. The patient also may develop an immune response to the human leukocyte antigen (HLA) type of the graft s cells and reject all platelet transfusions that do not match their own HLA system. The HLA system, found on blood platelets and lymphocytes, is more compHcated than, but similar to, the ABO blood group system of red cells. 

In some cases, density gradient solutions are used to separate a specific layer of cells. A solution, like FicoU or PercoU, with a mass density between the density of the cells that are to be collected and the other cells, is added to the blood product. 

Filtration Filtration (qv) is appHed in blood cell separation to remove leukocytes from ted blood cell (RBC) and platelet concentrates. Centtifugational blood cell separators do not reduce white blood cells (WBC) in red cell and platelet products sufficiently to avoid clinical complications such as GvHD and alloimmunization. A post-apheresis filtration step is needed to further reduce the WBC load. Modem filters are capable of a 3-log reduction in white cell contamination of the blood product, eg, apheresis single-donor platelet units having a typical white cell contamination of 5 x 10 white cells in 4 x 10 platelets can be reduced to a 5 x 10 white cell contamination, a sufficiently low number to avoid severe transfusion reactions. 

The white cell adsorption filter layer is typically of a nonwoven fiber design. The biomaterials of the fiber media are surface modified to obtain an optimal avidity and selectivity for the different blood cells. Materials used include polyesters, eg, poly(ethylene terephthalate) and poly(butylene terephthalate), cellulose acetate, methacrylate, polyamides, and polyacrylonitrile. Filter materials are not cell specific and do not provide for specific filtration of lymphocytes out of the blood product rather than all leukocytes. 

Barrier Phenomenon. In red cell filtration, the blood first comes into contact with a screen filter. This screen filter, generally a 7—10-) m filter, does not allow micro aggregate debris through. As the blood product passes through the deeper layer of the filter, the barrier phenomenon continues as the fiber density increases. As the path becomes more and more tortuous the cells are more likely to be trapped in the filter. 

Surface Tension. Interfacial surface tension between fluid and filter media is considered to play a role in the adhesion of blood cells to synthetic fibers. Interfacial tension is a result of the interaction between the surface tension of the fluid and the filter media. Direct experimental evidence has shown that varying this interfacial tension influences the adhesion of blood cells to biomaterials. The viscosity of the blood product is important in the shear forces of the fluid to the attached cells viscosity of a red cell concentrate is at least 500 times that of a platelet concentrate. This has a considerable effect on the shear and flow rates through the filter. The surface stickiness plays a role in the critical shear force for detachment of adhered blood cells. 

J. J. Morgenthaler, ed.. Virus Inactivation in Blood Products, Karger, Basel, 1989. 

In 1983 the move to develop red cell substitutes intensified when it was recognized that the acquired immune deficiency syndrome (AIDS) could be transmitted by the blood-bome human immunodeficiency vims (HIV). Concern for the nation s blood supply followed. Since that time other retrovimses have been identified, efforts to screen blood not only for these agents but also for vimses that cause hepatitis have intensified, the indications for transfusion have been reevaluated, and the use of blood products has become much more efficient. More carehil screening of donors, testing of all donated units, and a general awareness in the donor population have all contributed to a decreased risk from transfusion-contracted AIDS. 

Outdated Human Blood. If clinical efficacy and safety of hemoglobin solutions can be shown, the demand for product would soon outstrip the supply of outdated human blood. About 12 million units of blood (1 unit 480 mL) are used in the United States each year, and only about 500,000 outdate. The primary use of blood is in intraoperative and emergency settings. The quantity of blood available for use in production of blood substitutes depends on safety and efficient usage of blood products as well as on the demands on blood suppHes. 

Biological medicines Biological therapeutics Blood products Vaccines Diagnostics... 

Cellular cytokines (interferons, G-CSF) and immune response modifiers originally produced from human cells, most often leukocytes, have now been replaced with recombinant products with well-defined structure/function. Futuristic advances in experimental hematology portend development of human blood cells produced from the hemopoetic stem cells. Yet for the foreseeable future, homologous blood donated by healthy, altruistic voluntary blood donors remains the principal source of safe and adequate supply of blood and blood products for transfusion therapy. 

The immune globulins are contraindicated in patients with a history of allergic reactions after administration of human immunoglobulin preparations and individuals with isolated immunoglobulin A (IgA) deficiency (individuals could have an anaphylactic reaction to subsequent administration of blood products that contain IgA). 

Dir. 2002/98/EC Human blood products Amended by Directive 2002/98/EC of the European... 

Different conformity assessment options are available, depending on the type of device and the level of associated risk. For lotv-risk devices, the manufacturer can make a declaration of conformity based solely on self-assessment, without the need for the involvement of a Notified Body. For all other devices Notified Bodies are required to perform one or more of the tasks outlined in Table 10.2. HIV and hepatitis tests and blood grouping tests represent the highest risk devices, as they are critical to ensuring the safety of blood and blood products. For example, a defective HIV test device could result in widespread infection in an unsuspecting population, whereas the detrimental effects ofan AIMD or a Class III device failure will just be confined to the individuals treated by the device. At this end of the risk spectrum. Notified Bodies are required to verify the applied quality system, the specific device design, and the... 

General Requirements for Blood, Blood Components and Blood Products Additional Standards for Human Blood and Blood Products Additional Standards for Diagnoshc Substances for Laboratory Tests Additional Standards for Miscellaneous Products... 

FDC Act Section 510, Registration of producers of drugs and devices Establishment Registration 21 CFR Parts 207 (drugs), 607 (blood/blood products) and 807 (devices)... 

Hepatitis C virus (HCV) Spherical particles 40 nm in diameter consisting of an inner core surrounded by an adherent lipid envelope The virus is spread through blood transfusions and blood products. Induces a hepatitis which is usually milder than that caused by HBV... 

Other important examples are blood and blood products, which are collected and processed in sterile containers, and plasma substitutes, for example dextrans and degraded gelatin. Dextrans, glucose polymers consisting essentially of (1 - 6) a-links, are produced as a result of the biochemical activities of certain bacteria of the genus Leuconostoc, e.g. L. mesenteroides (see Chapter 25). 

If intracranial hemorrhage is confirmed, administer 5-10 units of cryoprecipitate, evaluate laboratory results, and supplement blood products and platelets as deemed necessary (e.g., 2 units fresh frozen plasma [FFP], 6-8 units platelets)... 

Compare and contrast the relative advantages and disadvantages of crystalloids, colloids, and blood products in the treatment of hypovolemic shock. 

Three major therapeutic options are available to clinicians for restoring circulating blood volume crystalloids (electrolyte-based solutions), colloids (large-molecular-weight solutions), and blood products. 

Blood products are indicated in adult hypovolemic shock patients who have sustained blood loss from hemorrhage exceeding 1500 mL. 

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